Exhibits: The Big Picture

Imagine having eyes as powerful as a telescope. You would be able to see deep into space. Even a tiny portion of the sky would be filled with the stars of our own galaxy and the light of many distant galaxies. Your view would give you The Big Picture, the largest astronomical image ever produced.

Measuring in at 152 feet long by 20 feet high, The Big Picture is also by far the largest exhibit in the new Gunther Depths of Space exhibit hall, where a visitor's perspective shifts from an earthbound view to one encompassing vistas we've encountered through our exploration of space.

Produced in porcelain enamel, this panoramic wall displays a single, astronomical image of real observational data. It covers a part of the sky that contains more than a million galaxies, stars, and other celestial objects. Though rendered onto a surface material usually used for art pieces, The Big Picture is actually a scientific data set displayed in image form at the resolution limits of the telescope and camera used to capture the data. In its immensity, detail, and execution, The Big Picture is unlike anything ever undertaken in public astronomy or porcelain display.

Because The Big Picture can be viewed at various distances across the floor and mezzanine of the Gunther Depths of Space, a visitor's perception of the objects in the picture changes with proximity to the wall. For example, a visitor viewing an individual spot of light on the wall from 65 feet away might assume it to be a star, but when directly in front of the wall it may transform into a multi-armed spiral galaxy. The Big Picture draws visitors in for closer examination.

The Big Picture Exhibit

C&G Partners, the design firm for the Observatory's new exhibit program, proposed The Big Picture concept in early 2001. Observatory Director E. C. Krupp and Caltech Professor George Djorgovski identified the area of the sky targeted for the display. Some key attributes of The Big Picture:

- 114 photo panels, each measuring 6 feet 8 inches high by 4 feet wide, produced in porcelain enamel
- 152 feet wide (38 panels), 20 feet high (3 panels)
- 3040 square feet total size
- Image is 7.4 gigabytes in size, drawn from over 200 gigabytes of raw data

The Big Picture Image

The Big Picture shows a tiny slice of the universe --roughly the small amount of the night sky (in the constellation Virgo the Maiden) that your index finger would cover if you held it about a foot from your eyes. It is an area of sky 15.2 degrees wide and 2.0 degrees high; if you looked at this part of the night sky with your naked eye, you might see just a few stars. As observed through the Samuel Oschin Telescope, however, The Big Picture image features over one-and-a-half million visible galaxies, stars, and other celestial objects.

Galaxies About a million Millions and billions of light-years
Stars Hundreds of thousands Tens to thousands of light-years
Quasars About a thousand Billions of light-years
Asteroids Hundreds Hundreds of millions of miles
Comets At least one Hundreds of millions of miles

The largest visible features in the image are galaxies, many of which lie about 50 million light-years from Earth. This is the heart of the Virgo Cluster, a collection of more than 2,000 galaxies distributed across 10 million light-years of space. Project officials selected it as the focus for The Big Picture because the cluster represents our first step into the large-scale structure of the universe.

Acquiring and Processing the Image

The Big Picture is the work of astronomers, data-processing experts, and imaging scientists from the California Institute of Technology, Yale University, and Palomar Observatory, sponsored by the National Science Foundation. The image is part of the Palomar-Quest astronomical sky survey, which is systematically mapping the universe out to the most distant quasars, more than 10 billion light-years away. The Palomar-Quest Survey team, led by Caltech Professor George Djorgovski, used the 48-inch Samuel Oschin Telescope on Palomar Mountain to acquire the data for The Big Picture. The individual images were captured by the Quest Camera, one of the largest and most precise detectors ever built to survey the sky. It has 112 CCD chips at its heart and scans the sky in 4.6-degree-wide strips.

The Palomar-Quest Survey team made observations on 20 nights between March 2004 and April 2005 to collect the necessary imagery. The team then worked with the Caltech Center for Advanced Computing Research to process the data into a single file. Dr. Djorgovski, in close consultation with Dr. Bruce Bohannan, Exhibit Content Scientist, then went through an extensive review of the data to identify any anomalies and to set the parameters for color and appearance. After several reviews with Dr. Krupp and Dr. Bohannan, the data set was approved.

The team then subdivided the final 2.46-gigapixel image into 114 individual images, each corresponding to one of the panels. Finally, three graphic experts at Caltech spent hundreds of hours systematically reviewing each image panel for accuracy. The result was the final set of production files for The Big Picture.

Producing and Installing The Big Picture

Two parallel efforts were required to produce and install The Big Picture, both overseen by the Observatory's exhibit fabricator, Maltbie, Inc.

First, the files were translated into porcelain panels. The design team chose porcelain as the material for The Big Picture because of its beauty and its durability. It is resistant to fading, rust, mildew, moisture, oxidation, fire, vandalism, and other damage.

Maltbie contracted with Winsor Fireform, Inc., of Tumwater, Washington, to produce the panels. The size of the Winsor kilns was actually the factor that determined the maximum size of the panels. Winsor produced a series of test panels for review by the Observatory team before being approved for production. One of the key challenges was the large amount of black on each panel and the need for that black (and all other colors) to be consistent across all 114 panels.

- The Big Picture is largest photographic image ever produced on porcelain enamel
- The final panels were produced over six months (October 2005 to March 2006)
- Each panel required seven firings in the kiln
- Production of the panels required 11,400 pounds of porcelain enamel, or roughly 100 pounds per panel

The second fabrication effort involved producing the steel frame and surface on which the porcelain panels are mounted. Maltbie began installing the frame in late 2005 and completed it in January 2006.

The porcelain panels from Winsor began arriving at the Observatory in early February, with installation on the wall beginning a few weeks later. The last panels were mounted on April 26, 2006.

The Team Behind the Big Picture

Palomar-Quest Survey Team

The Palomar-Quest astronomical sky survey is using the Quest Camera on the Samuel Oschin Telescope at Palomar Observatory to map systematically the universe out to the most distant quasars, more than 10 billion light-years away. Team members who contributed significantly to the creation of The Big Picture include:

- From the California Institute of Technology: Prof. S. George Djorgovski (the survey Co-Principal Investigator); Drs. Ashish Mahabal, Roy Williams, Matthew Graham, and Andrew Drake; graduate students Milan Bogosavljevic and Ciro Donalek; digital image experts Leslie Maxfield, Simona Cianciulli, and Radica Bogosaljevic; and other personnel at Caltech.

- From Yale University: Prof. Charles Baltay (the survey Co-Principal Investigator): Drs. David Rabinowitz and Nancy Ellman; graduate student Anne Bauer; and other personnel at Yale.

Professor S. George Djorgovski

S. George Djorgovski is a Professor of Astronomy, the Co-PI of the Palomar-Quest sky survey, and a co-Director of the Center for Advanced Computing Research at Caltech. He was also the PI of the previous Digital Palomar Observatory Sky Survey, and one of the founders of the National Virtual Observatory, among many other professional functions. He received his Ph.D. from U.C. Berkeley, and was a Harvard Junior Fellow before joining the Caltech faculty. Prof. Djorgovski is an author or coauthor of several hundred professional publications, including over 200 papers in refereed journals, many of them reporting significant new discoveries and advances. He received a Presidential Young Investigator Award and an Alfred P. Sloan Foundation Fellowship, among other honors and distinctions. His scientific interests include studies of the distant universe, formation and evolution of galaxies and their fundamental properties, quasars, cosmic gamma-ray bursts, globular star clusters, stellar dynamics, digital sky surveys, and many other astronomical topics; his more recent interests include a broader study of the ways in which information technology is revolutionizing science in general.

Winsor Fireform, Inc.

Winsor Fireform, Inc., is the inventor of an innovative, high-resolution photographic reproduction technology in porcelain enamel. The results of this process are images of unparalleled clarity that are durable and resistant to all of nature's elements. Once Winsor introduced the National Park Service to the high quality results possible with their proprietary process, they became a primary contractor for the Wayside Division; the company remains so a decade later.

Today, Winsor Fireform, under the management of President, Bryan R. Stockdale, supplies its products on an international scale to clients that include outdoor parks, historic sites, museums, the White House, Grand Canyon National Park, the Washington Monument, the Brooklyn Zoo, and New York's Times Square. They are the recognized industry leader in high-quality porcelain-on-steel imaging and continue to earn respect for a host of innovations in color matching, edge treatments, and image resolution. Winsor Fireform stands for superb quality, superior customer service, and unsurpassed technical expertise.